CEDAR RAPIDS — Sen. Chuck Grassley raised the specter of impeachment if Democrats win control of the U.S. House this fall.

Commenting on prospects that the re-election of 1st District Rep. Rod Blum and 3rd District Rep. David Young may be written off as “lost causes,” Grassley defended their work, the work of the GOP-controlled Congress and progress under President Donald Trump.

“Just look at the good policy that has come out of this Congress and this administration,” Grassley said Wednesday, “and the good economy.”

There has been speculation recently that national Republican groups are writing off the most vulnerable incumbents to concentrate on those races the GOP seems more likely to win. Blum, who is seeking a third term, has been rated as the most vulnerable House incumbent, and handicappers have classified the race as “toss up” or “leans Democratic.” He faces Democratic State Rep. Abby Finkenauer.

Young, also seeking a third term, is being challenged by Democrat Cindy Axne. Their race is being labeled a “toss up.”

As someone who sees the work of Congress “from the inside,” Grassley called the two Iowa Republicans “incredibly effective advocates for Iowa (who) work hard for Iowans every day.”

Challengers don’t see their work “and it misleads them to some extent,” he added.

Most importantly, Grassley told reporters, “If (Rep. Nancy) Pelosi takes over the House, the president will be under impeachment, and that’s the end of all the good work this president has done” that previous presidents — Democrat and Republican — were unable to accomplish, he said.

That includes getting NATO partners to increase their military spending and renegotiating trade agreements with Europe and China, and updating the North American Free Trade Agreement.

“Who would have thought a year ago we would be relieved of the potential of a nuclear attack from North Korea or we’d even be negotiating with North Korea?” he said. “This president has done that.”

Asking whether Blum and Young are lost causes ignores the benefit to Republican incumbents of a strong economy and progress on the range of policy issues, Grassley said.

The prospects that Democrats might win control of the Senate is likely to encourage them to continue to stall the confirmation of Trump’s Supreme Court nominee, Bret Kavanaugh, said Grassley, chairman of the Judiciary Committee.

“That’s what they’ve been doing since July 9,” he said. “So it’s no different now. They’re going to do everything they can to stall it.”

However, Senate Majority Leader Mitch McConnell has said Kavanaugh will be confirmed by Oct. 1.